×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

head loss and also discharge of a tank througha vertical pipe

head loss and also discharge of a tank througha vertical pipe

head loss and also discharge of a tank througha vertical pipe

(OP)
I have two different questions.

First one goes like this. I have need to size a pump and am calculating the head loss. The major requirement is that there must be 70psi coming out of the discharge end into atmospheric pressure. There is also a 35 foot elevation change. Am I correct in saying that with these two combined, and neglecting pipe friction losses, I already have calculated 196 feet of head?

The second question is this. In a 4x8x4 chest, there is a verticle pipe. The verticle pipe only extends about 30 inchs vertically into the tank. When water rises above this level, it flows through the pipe. During operation, water will be about 7 inches above the end of the pipe. What i need to know is, what flow in GPM will go through that pipe. The flow into the tank varies.  The pipe is 10 inches in diameter.

Can anyone help me with these questions?
thanks

RE: head loss and also discharge of a tank througha vertical pipe

If your first question has right requirement and pump inlet pressure is 0 psig, your calculation would be correct. But, it's impossible to have 70 psi at end of pipe discharging into atmosphere. If the location you check pressure is a little upstream from discharge nozzle and nozzle size is small enough, 70 psi may possible.

For the second question, I assume pipe end is open to atmosphere. Major factors determining flow rate are 1) pipe head loss that depend on length, number of elbows, valves,...
2) height difference between outlet of the pipe and water level.

RE: head loss and also discharge of a tank througha vertical pipe

For liquids you loose 1 velocity heigh when going into the pipe (from the tank) and another 1/2 when discharging (liquids usually dont choke).

To get dP in head multiply 1.5 with V^2/(2g).
V is with respect to the liquid velocity in the pipe.

Best regards

Morten

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources